This invention relates to containers for holding fluids under extreme high pressures and, more particularly, to a container for diving or other gas containing tanks formed of stainless steel alloy that ruptures along split lines under excessive pressures rather than fragmenting.
Tanks used for fluids such as air or other gases and mixtures thereof are often subjected to considerable stress both because of the high pressures of the fluids within the tanks and because of pressures exerted due to conditions during the handling and use of such tanks. Where a tank is used to dispense oxygen in a hospital or on an emergency vehicle, as well as in applications such as for scuba diving, rough handling or extreme conditions of an environmental nature may occur. It will be appreciated that a rupturing of such tanks may pose serious threats of injury to a user if the rupture results in fragmentation of the tank. Accordingly, it is important that such tanks rupture without fragmentation if they are subjected to extremely abnormal conditions. Moreover, it is important to provide as much tensile strength as possible.
In this latter connection, such tanks can be increased in strength by manufacturing them with heavier walls. However, this solution may result in an extremely heavy tank unsuitable for application requiring portability. Also, the fragmentation problem due to the characteristics of the material of the tank may still be present.
Accordingly, it is an object of this invention to provide a high pressure container which will be light in weight and substantially symetrical in design and which will be corrosive resistant and upon failure split instead of fragmenting.
Another object of this invention is to provide a high compression tank, for scuba divers, in which the tank is of unitary integral construction from a corrosive resisting alloy having in excess of 16.5% chromium and in excess of 24% combination of chromium, manganese and nickel, which container is then annealed by heat treating to provide a container having in excess of 110,000 p.s.i. yield stress, and upon failure splits and does not fragment.
A more specific object of this invention is to provide a novel method for producing a high strength tank for fluids which is of unitary, integral construction and is formed from an alloy which by weight consists essentially of about 16.18% chromium, about 7.89% nickel, about 0.8% titanium, about 0.4% aluminum, up to about 0.5% silicon, about 0.88% manganese, about 0.04% sulphur, about 0.04% phosphorus, up to about 0.04% carbon and balance iron.